Molecular Iodine: A Powerful Catalyst for the Knoevenagel Condensation of Isatins with Malononitrile

Table 2

The Knoevenagel condensation of isatins with malononitrile catalyzed by I₂^a.

Entry	R^1	R^2	Time (min)	Product	Yield (%)^b	m.p. (°C)
1	H	H	5	3a	97	235–237
2	H	Cl	5	3b	98	220–222
3	H	Br	5	3c	95	223–225
4	H	F	3	3d	99	230–231
5	H	NO2	3	3e	98	263–265
6	CH3	H	5	3f	94	234–235

^aReaction conditions: isatins (1 mmol); malononitrile (1 mmol); I₂ (0.1 mmol); EtOH (10 mL); 60°C.
^bIsolated yield.